Recent analyses suggest that young adults drink more often and consume more alcohol than older adults. This vulnerability to alcohol misuse has disturbing implications because alcohol is frequently implicated in a variety of public health problems-motor vehicle crashes, hospital admissions for trauma, acts of aggression and violence, high-risk sexual behavior, and criminality. Young adults clearly account for a substantial proportion of alcohol-related accidents; in addition, alcohol plays a significant role in young adult deaths due to accidents, homicide, and suicide. While the association between alcohol and many public health problems is clear, our knowledge of how to mitigate the young adult's vulnerability to alcohol misuse and alcohol-related problems is limited. This study seeks to clarify the links between adolescent drinking and young adult behavior, thereby providing a basis for identifying high-risk young adults whose earlier drinking has escalated over time and\or negatively affected their functioning and well-being. It also seeks to help us identify the gaps between the need for health care and what young adults actually get in the form of health services. The study's specific aims are: To examine the patterns and predictors of stability and change in alcohol use and misuse from adolescence to young adulthood, with specific emphasis on similarities and differences across gender and different racial/ethnic groups. To assess the consequences of alcohol use and misuse during adolescence on young adult functioning and well-being; and To identify the links between drinking and health service utilization among young adults. Among the hypotheses to be tested are: 1) Alcohol misuse will be more strongly related to the use of emergency services than to the use of other medical services such as doctor visits, clinic services, etc.; 2) Women who misuse alcohol will seek treatment in the mental health sector more often than in the alcohol treatment sector; 3) Whites are more likely to use alcohol-related services than Blacks or Hispanics, even controlling for drinking behavior; and 4) Prior deviance, school problems, and trouble at home will have a stronger impact on alcohol-related problems than on alcohol consumption. This 3-year effort will involve collecting new data from over 5000 members of the RAND adolescent panel (now aged 23 or 24) and analyzing-hose data in conjunction with existing information on panel members' earlier alcohol use, other drug use and related behavior and attitudes. The existing data base includes over 5,000 West Coast adolescents tracked between grades 7 and 12; extending it offers a rare opportunity to examine changes in- alcohol use from adolescence to young adulthood, as well as the link between early drinking and later adult functioning and use of health services.